School of Science, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
College of Electronic and Optical Engineering & College of Flexible Electronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
J Mol Graph Model. 2024 Dec;133:108868. doi: 10.1016/j.jmgm.2024.108868. Epub 2024 Sep 16.
Hydrate-based CO storage is a cost-effective and environmentally friendly approach to reduce carbon emission, and the addition of hydrate promoters has shown a promising avenue for enhancing CO hydrate formation. In this work, the promotion mechanism and promotion performance of five different hydrate promoters (denoted as DIOX, CP, THF, THP, and CH) were investigated and compared by first-principles calculations and molecular dynamics simulations. The results show that the hydrate promoters prefer to singly occupy 56 cages of the sII hydrate, and CO molecules can singly occupy 5 cage or multiply occupy 56 cages. The cohesive energy density indicates that the optimum CO storage capacity can reach up to ∼28 wt%. The stabilization effects of hydrate promoters on the hydrate stability should follow the order of CP > CH > DIOX > THF ≈ THP. The hydrate promoters can increase the water-water interactions, and the molecular diffusivity shows that the dynamic stability of the hydrates is THP ≈ CH > CP > DIOX > THF. Further, the hydrate promoters can accelerate the hydrate formation kinetics, which reduce the induction time and increase the nucleation and growth process.
水合基 CO 储存是一种经济且环保的减少碳排放的方法，而添加水合促进剂已被证明是一种增强 CO 水合物形成的有前途的途径。在这项工作中，通过第一性原理计算和分子动力学模拟研究并比较了五种不同水合促进剂（表示为 DIOX、CP、THF、THP 和 CH）的促进机制和促进性能。结果表明，水合促进剂优先单独占据 sII 水合物的 56 个笼，CO 分子可以单独占据 5 个笼或多次占据 56 个笼。内聚能密度表明，最佳的 CO 储存容量可达约 28wt%。水合促进剂对水合物稳定性的稳定作用应遵循 CP>CH>DIOX>THF≈THP 的顺序。水合促进剂可以增加水分子间的相互作用，而分子扩散系数表明水合物的动态稳定性为 THP≈CH>CP>DIOX>THF。此外，水合促进剂可以加速水合物的形成动力学，从而缩短诱导时间并增加成核和生长过程。
